Slice the turnip with a mandolin until you get 30 slices. Lay out a clean kitchen towel and sprinkle ¼ tsp of salt. Let sit for 10 minutes, then place another kitchen towel on top and press to release moisture.
Shred about 1/8 of a cabbage head until you have 1 cup of shredded cabbage. Then, finely chop the shredded cabbage. Transfer to a bowl.
Finely chop the scallion, mince the garlic, grate the ginger, and add them to the bowl. Add the chicken, sake, sesame oil, ½ tbsp soy sauce, 1/2 tsp salt, and black pepper.
Wash your hands and mix in with your fingers. Lay out the turnip slices on a clean surface. Add about 2 tbsp of filling to half of each circle. Fold the turnip slices in half over the filling.
Add 1 tbsp of oil to a skillet and place over medium heat. Arrange 15 gyozas in a single layer. Cook for a couple of minutes until the bottom begins to brown.
Flip all the gyozas and drop the heat to medium-low. Cover the skillet with a lid and let steam for 5-7 minutes until the meat is fully cooked. Transfer to a plate and repeat with the other 15 gyozas.
While the gyozas cook, make the dipping sauce. In a small bowl, whisk together 2 tbsp soy sauce, rice vinegar, and chili flakes. Set the dipping sauce aside.
Place the Keto gyozas on a serving plate. Place the dipping sauce in a small bowl and place it next to the gyozas. Serve immediately!